Re: [usb-gadget-udc] question about null check after calling phys_to_virt() function

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Hi Felipe,

Quoting Felipe Balbi <balbi@xxxxxxxxxx>:

Hi,

"Gustavo A. R. Silva" <garsilva@xxxxxxxxxxxxxx> writes:
Hello everybody,

While looking into Coverity ID 145958 I ran into the following piece
of code at drivers/usb/gadget/udc/amd5536udc.c:852:

} else if (i == buf_len) {
         /* first td */
         td = (struct udc_data_dma *)phys_to_virt(
                                 req->td_data->next);
         td->status = 0;
} else {
         td = (struct udc_data_dma *)phys_to_virt(last->next);
         td->status = 0;
}

if (td)
         td->bufptr = req->req.dma + i; /* assign buffer */
else
         break;

The issue here is that _td_ pointer is being dereferenced before null check.

After searching for calls to phys_to_virt() function, I've noticed
that is not common at all to test the returned address value.

So either the null check at line 862 is not needed or a null check
before each td->status = 0; needs to be added.

just remove the previous null check


I get it.

Thanks!
--
Gustavo A. R. Silva






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